JP3934418B2 - Calcium phosphate hardened body, calcium phosphate porous body and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hardened calcium phosphate having a strength that is less likely to cause cracking and is easy to process, and a calcium phosphate porous body that is obtained from this hardened body and has pores that are open and continuous on the surface. It relates to a manufacturing method. The calcium phosphate porous material of the present invention is widely used for bone prosthetic materials such as artificial bones, artificial tooth roots, and artificial joints.
[0002]
[Prior art]
In recent years, various materials such as a hydroxyapatite sintered body have been developed as bone prosthetic materials. Especially when a porous material is inserted into a bone defect, collagen fibers and then new bone enter the pores of the porous body from the living body side, and finally the pores inside the porous body are completely filled with new bone. It is an effective material as a bone prosthetic material, because the strength of the porous material itself is improved and sufficient adhesion strength with living bone is obtained.
Thus, in order for the new bone to enter the inside of the porous body, it is necessary that the pores are opened on the surface of the porous body, and the pore diameter is 10 μm or more and is continuous from the surface. As a method for producing such a porous body, as described in JP-A-5-246773, a method for producing a porous body using a bead-like thermally decomposable substance, or JP-A 63-181756 is disclosed. As described in Japanese Laid-Open Patent Publication No. 4-83811, a method for obtaining a sponge-like porous body by coating ceramic powder on the skeleton surface of a sponge-like thermally decomposable substance and baking it. As described above, a method for producing a porous body using a foaming agent is known.
However, among these production methods, in the method using a bead-like thermally decomposable substance or a foaming agent, the formed pores (pores) are spherical, so that continuous pores opened on the surface are formed. It is difficult. Furthermore, even if a continuous hole is formed from the surface to the deep inside, a neck is formed between the holes, so that a portion having a small hole diameter (a hole diameter of less than 10 μm) is generated in the continuous hole. Further, in order to make the hole diameter of the neck forming portion 10 μm or more, the inner diameter (maximum hole diameter) of the spherical hole must be further increased. However, if the diameter of the spherical hole is further increased, the strength of the porous body is unnecessarily small. It becomes a thing.
In addition, in the method of obtaining a porous body by coating a ceramic powder on a sponge-like thermally decomposable substance, it is difficult to produce a porous body with high strength because the porosity is large and the skeleton of the porous body becomes thin. It is.
[0003]
[Problems to be solved by the invention]
As a method for solving the above problems, there is a method described in Japanese Patent Laid-Open No. 61-174179. In this manufacturing method, methanol or the like that volatilizes at a low temperature is used as a solvent for the slurry, and the combustible material structure having a three-dimensional structure is impregnated with the slurry. Thereafter, the methanol in the slurry is volatilized by heating to obtain a cured product. Thereafter, the flammable material structure is heated to remove the resin to obtain a degreased body. Next, this degreased body is fired to produce a porous body.
However, in this manufacturing method, since the curing for obtaining the cured body is performed by volatilizing the solvent, cracks are likely to occur in the cured body. Furthermore, since the strength of the cured body is reduced, it is difficult to handle the cured body, and it is difficult to process the cured body.
The present invention has been made in order to solve the above-mentioned problems. A hardened calcium phosphate having a strength that is hard to crack and that can be easily processed is prepared. An object is to obtain a calcium phosphate porous body having pores having a continuous maximum diameter (hereinafter simply referred to as pore diameter) and a method for producing the same.
[0004]
[Means for Solving the Problems]
  In the cured calcium phosphate of the present invention, a slurry containing a monomer, a calcium phosphate compound powder, and a solvent is filled in a mold having a hole forming means, and the slurry is cured by polymerizing the monomer, and then demolded. It is obtained by doing.
  And in invention of Claim 1,The hole forming meansIs, A rod-shaped protrusion formed on the inner wall surface of the moldIs.
  In the invention of claim 2,The hole forming meansIs, Rod-shaped protrusions formed on the inner wall surface of the mold, and a thermally decomposable substance filled in the moldIs.
  Furthermore, the thermally decomposable substance may have voids having a three-dimensional network structure inside.
  In addition, the monomer may be composed mainly of at least one of acrylamide, methacrylamide, acrylic acid, methacrylic acid, acrylonitrile, and maleic acid.
  Furthermore, the calcium phosphate porous body of the present invention is characterized in that the above-mentioned calcium phosphate cured body is degreased and fired.
  Moreover, the manufacturing method of the calcium phosphate porous body of the present invention is characterized in that the above-mentioned calcium phosphate cured body is degreased and fired.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
A calcium phosphate cured body (hereinafter simply referred to as a cured body) is a slurry in which a monomer, a calcium phosphate compound powder, and a solvent are mixed, filled into a mold, and then the slurry is cured by polymerizing the monomer. Manufactured by demolding.
[0006]
Any “monomer” may be used as long as it is gelled and cured by the addition of an initiator or heating, but is preferably an organic monomer. The organic monomer is preferably a water-soluble organic monomer such as acrylamide, methacrylamide, acrylic acid, methacrylic acid, acrylonitrile, maleic acid, and acrylamide is particularly preferable. Only one type of the above monomers may be used, or two or more types may be used in combination. Moreover, when using 2 or more types as said monomer, what has acrylamide as a main component is more preferable. In addition, the above-mentioned “mainly comprising acrylamide” means that acrylamide is usually contained in an amount of 90 parts by mass or more, preferably 95 parts by mass or more when the total mass of the monomer is 100 parts by mass.
Furthermore, in addition to the above monomers, a crosslinkable monomer can be contained in order to adjust the strength of the cured product. As the crosslinkable monomer, for example, one kind selected from vinyl ether of ethylene glycol, vinyl ether of diethylene glycol, allyl ether of diethylene glycol, allyl ether of ethylene glycol, acrylic acid ester of ethylene glycol, and methacrylic acid ester of ethylene glycol Although 2 or more types of compounds etc. are mentioned, it is not specifically limited. Moreover, this crosslinking | crosslinked monomer can also use only 1 type and may use 2 or more types together. At this time, this crosslinkable monomer can be 1-15 mol when the said monomer (except a crosslinkable monomer) is 100 mol.
[0007]
The content of this monomer (including the crosslinkable monomer) can be 1 to 30 parts by mass, preferably 1 to 15 parts by mass, when the mass of the calcium phosphate compound powder is 100 parts by mass. . When the monomer content is less than 1 part by mass, it is difficult to obtain a cured product having sufficient strength. When the monomer content exceeds 30 parts by mass, the sinterability decreases and the strength of the fired product itself decreases. Therefore, it is not preferable.
[0008]
Examples of the “calcium phosphate compound powder” include hydroxyapatite powder, α-type tricalcium phosphate powder, β-type calcium phosphate triphosphate powder, dolomite, tetracalcium phosphate powder, calcium dihydrogen phosphate anhydrous powder, diphosphate phosphate Examples thereof include calcium hydride hydrate powder and octacalcium phosphate powder, and these may be used alone or in combination of two or more.
The calcium phosphate compound powder also includes a powder that forms the above calcium phosphate compound (mixture) after firing. For example, a mixed powder of hydroxyapatite and phosphate glass frit may be used. When this mixed powder is used, the glass frit and hydroxyapatite react and sinter after firing, and a composite of hydroxyapatite and tricalcium phosphate is obtained. can do.
In particular, it is preferable to use a raw material powder that becomes a composite of tricalcium phosphate and hydroxyapatite after firing.
[0009]
The “solvent” is not particularly limited as long as it dissolves the monomer that gels and hardens upon addition of an initiator or heating, but water is preferably used from the viewpoint of handling. When water is used as the solvent, the type of water is not particularly limited, and pure water, distilled water, or the like can be used. Furthermore, it is preferable that the volume ratio of the solvent and the calcium phosphate compound powder is 0.6 to 5.0, more preferably 1.0 to 2.0, as the volume ratio of the solvent / calcium phosphate compound powder. When this quantitative ratio is less than 0.6, the slurry has a high viscosity, and it is not easy to fill the mold. On the other hand, when the quantitative ratio exceeds 5.0, the slurry has a low viscosity and is easy to handle. However, it is not preferable because the strength of the cured body is not sufficient.
[0010]
Furthermore, in the present invention, the slurry is cured by polymerizing the monomer. Examples of the polymerization initiator used at this time include ammonium peroxosulfate, and it is necessary to select an initiator suitable for the type of monomer used. Furthermore, the addition amount of this polymerization initiator can be 0.1-1 mass part when a solvent is 100 mass parts. Furthermore, a catalyst can be added, and the polymerization rate can be controlled by the type and amount of the catalyst. Further, curing may be started or accelerated by heating.
[0011]
In addition, a dispersing agent can be further blended in the slurry in order to uniformly disperse the calcium phosphate compound powder and improve the fluidity of the slurry. Examples of the dispersant include polycarboxylic acid ammonium salt and polyacrylic acid ammonium salt. A dispersant suitable for the calcium phosphate compound powder to be used may be used. These dispersants may be used alone or in combination of two or more. The blending amount of the dispersant can be 0.01 to 10 parts by mass when the mass of the calcium phosphate powder is 100 parts by mass.
[0012]
In addition, the mold used in the present invention is, for example, a box-type that is open at one end (see FIGS. 1 and 2), and has a cross-sectional shape that is substantially circular, substantially elliptical, or rectangular. In addition, a polygon such as a pentagon can be used, and among these, a substantially circular (see FIG. 2) quadrangle (see FIG. 1) is preferable. Furthermore, the wall portion of this type may be formed integrally (FIG. 2), or a part thereof may be removable (FIG. 1).
[0013]
  The “mold” has “hole forming means” for obtaining holes opened on the surface. As the “hole forming means”, (1) a rod-like protrusion is formed on the inner wall surface of the mold, and the rod-like protrusion functions as a hole forming means;2) A rod-shaped protrusion is formed on the inner wall surface of the mold, and a thermally decomposable substance is filled in the mold, and both the protrusion and the thermally decomposable substance function as hole forming means.Used.
  That is, the protrusions can form holes that are open on the surface and have a continuous hole diameter at a predetermined value when the mold is removed. Also, when the slurry as a raw material is put in a mold filled with a pyrolyzable substance inside, and after curing, the cured body is demolded together with the pyrolyzable substance, and then the cured body is degreased and fired as described later In addition, by removing the thermally decomposable substance, it is possible to form holes that are open on the surface and have a hole diameter that is continuous at a predetermined value.
[0014]
The hole formed by the hole forming means may have a bottom or may not have a bottom as long as one of the holes is open on the surface. Of these, those having no bottom are preferred. Furthermore, this pore distribution is preferably substantially uniform throughout the porous body so as not to unnecessarily impair the strength of the porous body obtained by degreasing and firing the cured body. Further, the holes may be tapered as long as the strength of the porous body is not impaired.
[0015]
Further, in the case where the above-mentioned “hole forming means” is a protrusion formed on the inner wall surface of the mold, this protrusion can be formed on the inner surface of one or two or more wall portions as long as demolding is possible ( 1 and 2), usually, protrusions can be formed on the inner surfaces of the wall portions 1 to 3. Further, in the case of a mold in which protrusions are formed on the inner surface of the wall portion 2 or 3, it is preferable that these protrusions are formed so as to contact each other, and these protrusions are perpendicular to each other. It is preferable that they are formed so as to be opposed to each other (FIG. 1). By arranging the protrusions in this way, holes can be formed in one, two or three-dimensional directions. Moreover, the porosity can be improved by forming holes in the two-dimensional direction or the three-dimensional direction. Further, the protrusion is preferably perpendicular to the inner wall surface, but may not necessarily be perpendicular to the inner wall surface as long as it is linear. The rod-shaped protrusions may be tapered so that they can be easily removed by tapering or the like in consideration of ease of drawing (workability) at the time of removal. In addition, the rod-shaped protrusion may have a curve as long as it can be removed. In that case, it is preferable to use a deformable material such as rubber as the rod-shaped protrusion. Moreover, the length of the protrusion does not necessarily need to be uniform, and may be different depending on the application. Further, the protrusion may be formed so as to penetrate the slurry filled in the mold, or may be formed so as not to penetrate. The inner wall surface is preferably a flat surface, but may have a curved surface as long as it can be removed.
[0016]
Furthermore, the maximum dimension (hereinafter referred to as the cross-sectional diameter) of the cross-section of this protrusion can be 10 to 1000 μm, preferably 20 to 800 μm, more preferably 30 to 500 μm. When the cross-sectional diameter of the projection is less than 10 μm, it is difficult to produce the projection itself, and since the strength of the projection becomes weak and difficult to handle, it is not preferable for use. Furthermore, if it exceeds 1000 μm, it is not preferable because it has an excessive pore diameter with respect to invasion of living tissue and may reduce the strength more than necessary. The cross-sectional shape of the projection may be any shape, but may be a substantially circular shape, a substantially oval shape, a substantially rectangular shape, or a substantially polygonal shape such as a substantially triangular shape, a substantially rectangular shape, or a substantially pentagonal shape. Of these, a substantially circular shape and a substantially elliptical shape are preferable. Furthermore, as a specific example of the protrusion, when the cross-sectional diameter is several tens of μm, a material obtained by spinning a resin such as nylon or a material obtained by processing a photocurable resin with a laser can be used. When the cross-sectional diameter is several hundred μm, metal fibers or the like can be used, and a mold having protrusions can be produced by adhering these to the inner wall surface of the mold.
As a means for arranging the protrusion on the inner wall surface of the mold, although not particularly limited, for example, a method of drilling a number of holes in the wall according to the cross-sectional shape of the rod serving as the protrusion, and inserting and fixing the rod serving as the protrusion, A method for producing a mold wall having protrusions by gathering together rods having two-step outer circumferences as shown in FIGS. According to the latter method, it is possible to easily align the intervals between the protrusions with high accuracy, which is preferable as a mold manufacturing means. Further, microfabrication in which the cross-sectional diameter of the protrusions and the interval between the protrusions is 1000 μm or less is easy. In particular, by making the cross section of the portion with a large outer circumference circular, the processing of a rod having a two-stage outer circumference becomes easier. Moreover, the shape of the cross section of a part with a large outer periphery may have substantially polygonal shapes, such as a triangle, and the arrangement | sequence of a protrusion can also be adjusted with the shape of the cross section.
[0017]
When the hole forming means is a thermally decomposable substance filled in the mold, any material may be used as long as it is thermally decomposable, for example, polyurethane or Carbon or the like can be used. These thermal decomposable substances may be used alone or in combination of two or more. Further, the structure of the thermally decomposable substance may be anything as long as the voids are three-dimensionally connected, but the voids preferably have a three-dimensional network structure. Of the three-dimensional network structures, those in which the voids are continuous with substantially the same size (and the three-dimensional network structures having substantially the same thickness and wall thickness) are most preferable. As such a thermally decomposable substance, for example, an open-cell type polyurethane foam (usually, the size of the voids is substantially the same), a continuous pore-type carbon porous molded body, and the like are preferable. In addition, for example, a thermally decomposable substance such as a net-like body, an elbow-like body, or a rod-like body is filled in a mold, and a structure in which gaps are three-dimensionally connected to each other can be obtained.
[0018]
Next, a cured product is obtained through polymerization and curing. This polymerization reaction may be carried out in the air, but depending on the type of monomer and the like, there is a case where polymerization in a nitrogen atmosphere may be desirable, so that the polymerization reaction atmosphere is not particularly limited.
Next, the cured body is dried, degreased, and then fired to obtain the porous body of the present invention.
The drying is a step of volatilizing the solvent contained in the cured body. Examples of the drying method include heating and drying under reduced pressure, but are not particularly limited. In addition, when a solvent that does not easily volatilize and has a large surface tension is selected, it is more preferable to immerse the cured body in a volatile solvent having a small surface tension, perform solvent replacement, and perform a drying step.
The “degreasing” can be performed by heating the cured body at 150 to 900 ° C. for 0.5 to 10 hours. The degreasing atmosphere depends on the type of monomer used, but it is preferable to select an atmosphere suitable for the atmosphere or nitrogen atmosphere.
Moreover, said "baking" can be performed by heating the degreasing | hardened body at 900-1600 degreeC, Preferably it is 1000-1500 degreeC for 1 to 20 hours, Preferably it is 1 to 10 hours.
In the case of using a mold filled with a thermally decomposable substance as a hole forming means while the polymer of the monomer existing inside the cured body is decomposed and removed during the degreasing and / or firing step. This thermally decomposable substance is also decomposed and removed at this time.
[0019]
【Example】
  1. Production of hardened calcium phosphate and porous calcium phosphate of the present invention
  FruitExperimentExample 1(Example)
  For 100 parts by mass of pure water as a solvent, 15 parts by mass of acrylamide as a monomer, 3 parts by mass of “Poise 503A” manufactured by Kao as a dispersant, 0.6 part by mass of tetramethylethylenediamine as a catalyst, and diethylene glycol diallyl as a crosslinkable monomer Ether and 1 part by mass of methylenebisacrylamide were dissolved in pure water.
A mixed powder (hereinafter simply referred to as a mixed powder) of 40 parts by mass of hydroxyapatite powder and 160 parts by mass of β-tricalcium phosphate powder was mixed with this aqueous solution.
  At this time, the total amount of the acrylamide and the crosslinkable monomer is 8 mass% when the mass of the mixed powder is 100 mass%, and the addition amount of the crosslinkable monomer is 2.6 when the acrylamide is 100 mol. The amount of the dispersant is 1.5 parts by mass when the mixed powder is 100 parts by mass. Moreover, the quantitative ratio of pure water and the said mixed powder is 1.5 by volume ratio (pure water / mixed powder).
  Thereafter, 0.5 parts by weight of a polymerization initiator (ammonium peroxosulfate) is added to this slurry (with respect to 100 parts by weight of pure water), and the slurry to which the polymerization initiator has been added is filled in the mold shown in FIG. did. The mold is a cube (inner shape) having a side of 2 cm, and 49 protrusions 10 are formed on the inner wall surfaces 1, 2, and 3, respectively. The length of the protrusion 10 is 2 cm. Furthermore, the cross section of the protrusion 10 is circular, and its diameter is 500 μm.
  Thereafter, the slurry was allowed to stand for 0.5 hour in a nitrogen humidification chamber to polymerize and cure the slurry. After polymerization is complete, demold and dry under reduced pressure.ExperimentAn example calcium phosphate cured body was obtained.
  Next, the obtained cured body is degreased by heating at 600 ° C. for 6 hours, and calcined at 1125 ° C. for 3 hours.ExperimentAn example calcium phosphate porous material was obtained.
[0020]
  FruitExperimentExample 2(Reference example)
  Real as slurryExperimentThe same raw materials and contents as in Example 1 were used, an initiator was added to this slurry, and the mixture was poured into a mold filled with polyurethane foam, and this slurry was polymerized and cured. This polyurethane foam is of the open cell type having a wall thickness of about 200 μm and three-dimensionally connected so that the thickness is substantially constant. The initiator and the amount added areExperimentSame as Example 1. In addition, the dimensions of the mold areExperimentSame as used in Example 1. Then the realExperimentThe actual process is the same as in Example 1.ExperimentObtain a cured product of the example, and then use this cured productExperimentThe actual process is the same as in Example 1.ExperimentAn example porous body was obtained.
[0021]
2. Preparation of calcium phosphate porous material of comparative example
  A mixed powder of hydroxide apatite powder and β tricalcium phosphate powder was dispersed in methanol to obtain a slurry. Moreover, the quantitative ratio of water and the mixed powder is 2.0 in terms of mass ratio of methanol / mixed powder. This slurryExperimentThe mold used in Example 1 was filled and cured by drying. Then, it demolded and the hardening body of the comparative example was obtained. This cured body was fired at 1125 ° C. for 3 hours to obtain a porous body of a comparative example.
[0022]
3. Performance evaluation
(1) Evaluation of cured body
  FruitExperimentIn the cured bodies of Examples 1 and 2 and Comparative Example, the presence or absence of cracks on the surface was visually observed. Also, realExperimentThe cured bodies of Examples 1 and 2 and Comparative Example were processed with a diamond bar to evaluate workability. As a result, it was confirmed that many cracks exist on the surface of the cured body (dry body) of the comparative example. Further, as a result of processing the cured body of the comparative example with a diamond bar, there was a problem that the cured body was missing during processing. In contrast to this,ExperimentIn the cured bodies of Examples 1 and 2, the presence of cracks was not confirmed. Furthermore, as a result of processing with a diamond bar, there was no particular problem and processing was easy.
(2) Evaluation of porous body
  FruitExperimentThe porous bodies of Examples 1 and 2 were observed and photographed with SEM (scanning electron microscope). FruitExperimentThe photographed results of the polished fracture surface in Example 1 are shown in FIGS.ExperimentThe imaging results of the fracture surface in Example 2 are shown in FIGS. As a result,ExperimentIn Example 1, it can be seen that a cylindrical hole having the same inner shape as the outer shape of the protrusion is formed, and the pores are partially joined at a portion where the pores intersect vertically. That is, it can be seen that pores communicating in a multidimensional manner can be formed when the pore-forming projections in each direction are in contact with each other. FruitExperimentIn Example 2, it was confirmed that three-dimensionally structured holes were continuously formed.ExperimentIn both Examples 1 and 2, it was confirmed that there was no constricted portion (neck) having a pore diameter of 10 μm or less. In addition, when the pore diameter was measured based on the above observation,ExperimentIn the case of Example 1, about 500 μm, actualExperimentIn the case of Example 2, it was about 200 μm. In addition, the surface was observed visually and it confirmed that it opened to the porous body surface.
[0023]
4). FruitExperimentExample effect
  There are many cracks on the surface of the cured body in the comparative example, and as a result of processing the cured body of the comparative example with a diamond bar, there is a problem that the cured body is missing during processing. It can be seen that the body is prone to cracking and difficult to process.
  In contrast to this,ExperimentIn the cured bodies of Examples 1 and 2, the presence of cracks was not confirmed. Further, as a result of processing with a diamond bar, there was no particular problem.ExperimentIt can be seen that the cured bodies of Examples 1 and 2 are less prone to cracking and have a strength suitable for processing.
[0024]
  In addition, thisExperimentIn the porous body of the example, a hole opened on the surface is formed, and each of the holes has a diameter of 500 μm (actual size suitable for allowing a living tissue to enter).ExperimentExample 1) or 200 μm (actualExperimentIt can be seen that it is continuous in Example 2).
  As a result,ExperimentThe porous body of the example has a pore structure that allows biological tissue to easily enter the pores.
[0025]
  As a result,ExperimentIn the example, a cured body that is hard to crack and has a strength that can be easily processed can be produced, and a porous body having pores that are open to the surface and have a continuous pore diameter is obtained from the cured body. be able to.
[0026]
  In the present invention, the above specific examples(Experimental example 1)However, the present invention can be variously modified examples within the scope of the present invention depending on the purpose and application.
  For example, realExperimentIn Example 1, a mold in which protrusions are formed on the inner wall surface is used. However, a mold in which protrusions are formed on the inner wall surface and open-cell polyurethane is formed inside may be used. Thereby, a porous body having a larger porosity and a more diverse and complicated pore structure can be obtained.
  Also, realExperimentIn Example 1, although the type | mold shown in FIG. 1 was used, in this invention, it is not limited to such a type | mold, For example, the type | mold as shown in FIG. 2 can be used. Further, a protrusion may be formed on the inner surface of the bottom of this mold. In the case where a protrusion is formed on the inner surface of the bottom of the mold shown in FIG. 2, a porous body in which holes are formed in a one-dimensional direction can be obtained.
  Also, realExperimentIn the mold of Example 1, it is also possible to use only the inner wall surface 1 or the inner wall surfaces 1 and 2 with the protrusions 10 formed thereon, so that a hole structure in a one-dimensional direction or a two-dimensional direction can be obtained. A cured product having the same can be produced.
  Further, the wall portions 14 and 15 may be removable, and protrusions may be formed on the inner wall surfaces of the wall portions 14 and 15. Thereby, a porosity can be improved more.
  In the case where the hole forming means is a thermally decomposable substance filled in the mold, the width of the gap is not constant, but a sponge-like polyurethane foam or a sponge-like carbon molded body can be used.
[0027]
【The invention's effect】
Since the calcium phosphate cured product of the present invention is obtained by curing a slurry by polymerizing a monomer, it is hard to generate cracks and has a strength that can be easily processed.
Moreover, the calcium phosphate porous body of the present invention has pores that are open on the surface and have a continuous pore diameter. For this reason, the invasion of the living tissue becomes easy and the biocompatibility is improved.
Furthermore, according to the method for producing a calcium phosphate porous body of the present invention, it is possible to produce a hardened calcium phosphate body having a strength that is difficult to generate cracks and is easy to process. A calcium phosphate porous body having continuous pores can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing a mold used in this example.
FIG. 2 is an explanatory view showing an example of a mold used in the mold of the present invention.
FIG. 3 is an explanatory view showing an example of a protrusion used in the present invention.
FIG. 4 is an explanatory view of FIG. 3 as viewed from the front.
5 is an explanatory view showing an SEM photograph (see scale in the figure) of the surface of a porous body in Example 1. FIG.
FIG. 6 is an explanatory diagram showing an enlarged view of FIG. 5 (see the scale in the figure).
7 is an explanatory view showing an SEM photograph (see scale in the figure) of the surface of a porous body in Example 2. FIG.
FIG. 8 is an explanatory diagram showing an enlarged view of FIG. 7 (see the scale in the figure).
[Explanation of symbols]
1, 2, 3; inner wall surface, 10, 21; projection, 11, 12, 13, 14, 15; wall portion, 20; upper inner wall surface.

Claims (6)

A slurry containing a monomer, a calcium phosphate compound powder and a solvent is filled in a mold having a hole forming means,
A cured calcium phosphate obtained by curing the slurry by polymerizing the monomer, and then demolding ,
The calcium phosphate cured body, wherein the hole forming means is a rod-shaped protrusion formed on the inner wall surface of the mold . A slurry containing a monomer, a calcium phosphate compound powder and a solvent is filled in a mold having a hole forming means,
A cured calcium phosphate obtained by curing the slurry by polymerizing the monomer, and then demolding ,
The calcium phosphate cured body, wherein the hole forming means is a rod-shaped protrusion formed on the inner wall surface of the mold and a thermally decomposable substance filled in the mold . The hardened calcium phosphate according to claim 2 , wherein the thermally decomposable substance has voids having a three-dimensional network structure therein. These monomers, acrylamide, methacrylamide, acrylic acid, methacrylic acid, acrylonitrile, calcium phosphate cured body according to any one of claims 1 to 3 as a main component at least one from among maleic acid. A calcium phosphate porous body, wherein the calcium phosphate cured body according to any one of claims 1 to 4 is degreased and fired. A method for producing a porous calcium phosphate, comprising degreasing and firing the hardened calcium phosphate according to any one of claims 1 to 4 .

Images